Reduced-volume radiotherapy for locally advanced NPC improves QOL without compromising efficacy

Abstract

Induction chemotherapy (IC) followed by concurrent chemoradiotherapy is the standard of care for patients with locoregionally advanced nasopharyngeal carcinoma (NPC). Most patients have considerable tumour shrinkage after IC, yet the radiotherapy target volume is calculated on the basis of the dimensions of the pretreatment tumour, which can result in debilitating toxicities owing to irradiation of surrounding functional structures. Now, data from a phase III trial demonstrate that reducing the radiation volume according to tumour shrinkage maintains local control and improves quality of life (QOL).

In this trial, 445 patients with previously untreated stage III–IVA NPC who had completed 3 cycles of gemcitabine–cisplatin IC were randomly assigned (1:1) to receive radiotherapy based on the post-IC versus pre-IC tumour volume, plus 2 or 3 cycles of concurrent cisplatin. For both groups, any areas of bony structural invasion observed prior to IC were included in the target volume, regardless of changes after IC. Non-inferior locoregional relapse-free survival (LRFS) was the primary end point.